xref: /linux/drivers/net/ethernet/intel/igc/igc_nvm.c (revision 3eb66e91a25497065c5322b1268cbc3953642227)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c)  2018 Intel Corporation */
3 
4 #include "igc_mac.h"
5 #include "igc_nvm.h"
6 
7 /**
8  * igc_poll_eerd_eewr_done - Poll for EEPROM read/write completion
9  * @hw: pointer to the HW structure
10  * @ee_reg: EEPROM flag for polling
11  *
12  * Polls the EEPROM status bit for either read or write completion based
13  * upon the value of 'ee_reg'.
14  */
igc_poll_eerd_eewr_done(struct igc_hw * hw,int ee_reg)15 static s32 igc_poll_eerd_eewr_done(struct igc_hw *hw, int ee_reg)
16 {
17 	s32 ret_val = -IGC_ERR_NVM;
18 	u32 attempts = 100000;
19 	u32 i, reg = 0;
20 
21 	for (i = 0; i < attempts; i++) {
22 		if (ee_reg == IGC_NVM_POLL_READ)
23 			reg = rd32(IGC_EERD);
24 		else
25 			reg = rd32(IGC_EEWR);
26 
27 		if (reg & IGC_NVM_RW_REG_DONE) {
28 			ret_val = 0;
29 			break;
30 		}
31 
32 		udelay(5);
33 	}
34 
35 	return ret_val;
36 }
37 
38 /**
39  * igc_acquire_nvm - Generic request for access to EEPROM
40  * @hw: pointer to the HW structure
41  *
42  * Set the EEPROM access request bit and wait for EEPROM access grant bit.
43  * Return successful if access grant bit set, else clear the request for
44  * EEPROM access and return -IGC_ERR_NVM (-1).
45  */
igc_acquire_nvm(struct igc_hw * hw)46 s32 igc_acquire_nvm(struct igc_hw *hw)
47 {
48 	s32 timeout = IGC_NVM_GRANT_ATTEMPTS;
49 	u32 eecd = rd32(IGC_EECD);
50 	s32 ret_val = 0;
51 
52 	wr32(IGC_EECD, eecd | IGC_EECD_REQ);
53 	eecd = rd32(IGC_EECD);
54 
55 	while (timeout) {
56 		if (eecd & IGC_EECD_GNT)
57 			break;
58 		udelay(5);
59 		eecd = rd32(IGC_EECD);
60 		timeout--;
61 	}
62 
63 	if (!timeout) {
64 		eecd &= ~IGC_EECD_REQ;
65 		wr32(IGC_EECD, eecd);
66 		hw_dbg("Could not acquire NVM grant\n");
67 		ret_val = -IGC_ERR_NVM;
68 	}
69 
70 	return ret_val;
71 }
72 
73 /**
74  * igc_release_nvm - Release exclusive access to EEPROM
75  * @hw: pointer to the HW structure
76  *
77  * Stop any current commands to the EEPROM and clear the EEPROM request bit.
78  */
igc_release_nvm(struct igc_hw * hw)79 void igc_release_nvm(struct igc_hw *hw)
80 {
81 	u32 eecd;
82 
83 	eecd = rd32(IGC_EECD);
84 	eecd &= ~IGC_EECD_REQ;
85 	wr32(IGC_EECD, eecd);
86 }
87 
88 /**
89  * igc_read_nvm_eerd - Reads EEPROM using EERD register
90  * @hw: pointer to the HW structure
91  * @offset: offset of word in the EEPROM to read
92  * @words: number of words to read
93  * @data: word read from the EEPROM
94  *
95  * Reads a 16 bit word from the EEPROM using the EERD register.
96  */
igc_read_nvm_eerd(struct igc_hw * hw,u16 offset,u16 words,u16 * data)97 s32 igc_read_nvm_eerd(struct igc_hw *hw, u16 offset, u16 words, u16 *data)
98 {
99 	struct igc_nvm_info *nvm = &hw->nvm;
100 	u32 i, eerd = 0;
101 	s32 ret_val = 0;
102 
103 	/* A check for invalid values:  offset too large, too many words,
104 	 * and not enough words.
105 	 */
106 	if (offset >= nvm->word_size || (words > (nvm->word_size - offset)) ||
107 	    words == 0) {
108 		hw_dbg("nvm parameter(s) out of bounds\n");
109 		ret_val = -IGC_ERR_NVM;
110 		goto out;
111 	}
112 
113 	for (i = 0; i < words; i++) {
114 		eerd = ((offset + i) << IGC_NVM_RW_ADDR_SHIFT) +
115 			IGC_NVM_RW_REG_START;
116 
117 		wr32(IGC_EERD, eerd);
118 		ret_val = igc_poll_eerd_eewr_done(hw, IGC_NVM_POLL_READ);
119 		if (ret_val)
120 			break;
121 
122 		data[i] = (rd32(IGC_EERD) >> IGC_NVM_RW_REG_DATA);
123 	}
124 
125 out:
126 	return ret_val;
127 }
128 
129 /**
130  * igc_read_mac_addr - Read device MAC address
131  * @hw: pointer to the HW structure
132  */
igc_read_mac_addr(struct igc_hw * hw)133 s32 igc_read_mac_addr(struct igc_hw *hw)
134 {
135 	u32 rar_high;
136 	u32 rar_low;
137 	u16 i;
138 
139 	rar_high = rd32(IGC_RAH(0));
140 	rar_low = rd32(IGC_RAL(0));
141 
142 	for (i = 0; i < IGC_RAL_MAC_ADDR_LEN; i++)
143 		hw->mac.perm_addr[i] = (u8)(rar_low >> (i * 8));
144 
145 	for (i = 0; i < IGC_RAH_MAC_ADDR_LEN; i++)
146 		hw->mac.perm_addr[i + 4] = (u8)(rar_high >> (i * 8));
147 
148 	for (i = 0; i < ETH_ALEN; i++)
149 		hw->mac.addr[i] = hw->mac.perm_addr[i];
150 
151 	return 0;
152 }
153 
154 /**
155  * igc_validate_nvm_checksum - Validate EEPROM checksum
156  * @hw: pointer to the HW structure
157  *
158  * Calculates the EEPROM checksum by reading/adding each word of the EEPROM
159  * and then verifies that the sum of the EEPROM is equal to 0xBABA.
160  */
igc_validate_nvm_checksum(struct igc_hw * hw)161 s32 igc_validate_nvm_checksum(struct igc_hw *hw)
162 {
163 	u16 checksum = 0;
164 	u16 i, nvm_data;
165 	s32 ret_val = 0;
166 
167 	for (i = 0; i < (NVM_CHECKSUM_REG + 1); i++) {
168 		ret_val = hw->nvm.ops.read(hw, i, 1, &nvm_data);
169 		if (ret_val) {
170 			hw_dbg("NVM Read Error\n");
171 			goto out;
172 		}
173 		checksum += nvm_data;
174 	}
175 
176 	if (checksum != (u16)NVM_SUM) {
177 		hw_dbg("NVM Checksum Invalid\n");
178 		ret_val = -IGC_ERR_NVM;
179 		goto out;
180 	}
181 
182 out:
183 	return ret_val;
184 }
185 
186 /**
187  * igc_update_nvm_checksum - Update EEPROM checksum
188  * @hw: pointer to the HW structure
189  *
190  * Updates the EEPROM checksum by reading/adding each word of the EEPROM
191  * up to the checksum.  Then calculates the EEPROM checksum and writes the
192  * value to the EEPROM.
193  */
igc_update_nvm_checksum(struct igc_hw * hw)194 s32 igc_update_nvm_checksum(struct igc_hw *hw)
195 {
196 	u16 checksum = 0;
197 	u16 i, nvm_data;
198 	s32  ret_val;
199 
200 	for (i = 0; i < NVM_CHECKSUM_REG; i++) {
201 		ret_val = hw->nvm.ops.read(hw, i, 1, &nvm_data);
202 		if (ret_val) {
203 			hw_dbg("NVM Read Error while updating checksum.\n");
204 			goto out;
205 		}
206 		checksum += nvm_data;
207 	}
208 	checksum = (u16)NVM_SUM - checksum;
209 	ret_val = hw->nvm.ops.write(hw, NVM_CHECKSUM_REG, 1, &checksum);
210 	if (ret_val)
211 		hw_dbg("NVM Write Error while updating checksum.\n");
212 
213 out:
214 	return ret_val;
215 }
216